It's True That Deficits No Longer Matter ...

No, not because "Modern" "Monetary" "Theory" (which isn't any one, let alone all, of those three things) is correct that a state can write itself blank checks and spend the sums forever with no consequences.

Rather because the US regime in particular is long past the point where those consequences can plausibly be avoided.

It's become permanently politically impossible for the regime to either raise taxes, or cut spending, or both, to the degree necessary to pay down the politicians' debt (yes, it's their debt, not yours).

At some point, the regime is going to default on the "national debt." It may admit that that's what it's doing, or it may try to pull some kind of transparent con, but either way the happy train gets derailed, at which point the regime slides right off the big pile of paper it's stacked up and into the dustbin of history.

My prediction as to the timing of the latter event is "no later than 2050.